Non-toxic and environmentally safe protective coatings are being developed in order to replace presently used systems, which are based on products which are, encountered with toxicological and environmental drawbacks, such as acrylics, urethanes and epoxy polymers manufactured from oil-based chemicals. Temporary water-based coatings based on polysaccharides have previously, been suggested for the protection of surfaces against unwanted contamination (cf. U.S. Pat. No. 5,017,237). Polysaccharides are generally non-toxic, biodegradable and non-allergenic. In order to be able to protect surfaces from aggressive chemicals, such as acids and bases neutralising, complex-forming or buffering systems can be incorporated into such protective coatings (cf. EP 751 837).
Recent developments have shown, that the stability of polysaccharides against weathering can be substantially improved by generating coating systems in which the coating product based on polysaccharides is transformed from liquid into gel in the process of drying into a protective film coating (cf. AU 682 594).
In order to develop the polysaccharide coating that can resist high concentrations of acid influence it was experienced that the high concentrations of buffering salts that were necessary to build high buffering capacity resulted in destruction of the film properties of the coating in regard to inter alia water resistance. The problem underlying the present invention was thus to find alternative neutralising/buffering systems having sufficient capacity to result in the formation of films of sufficient resistance to environmental influence.